Thursday, January 23, 2014

Sugilite

Sugilite is a relatively rare cyclosilicate mineral with the complex chemical formula KNa2(Fe,Mn,Al)2Li3Si12O30.

Sugilite was discovered in 1944 and is found in Japan, Canada and India. The most important occurrence was found in 1975 in the Kalahari Desert, northern South Africa. In 1979 a large deposit of gem grade sugilite was found 3200 feet below the original discovery. Sugilite is named for the Japanese geologist who discovered the first specimens. It is opaque with a waxy luster and ranges from a pale grayish lavender to a deep dark purple.

Sugilite is also known under the trade names of "Royal Lavulite" and "Royal Azel"

Sugilite crystallizes in the hexagonal system with prismatic crystals. It often contains black matrix wih reddish brown or yellowish blotches and ranges between 6 - 7.5 on the Mohs scale of hardness. Bright purple stones with little matrixing or blotches are the most valued. Gem grade sugilite is beautifully translucent and often brings a high price.